3. Iron can be produced when iron (III) oxide reacts with carbon monoxide gas.
Fe2O3 (s) + 3C0 (g) → 2 Fe (s) + 3CO2(g)
11.5 g of Fe2O3 reacts with 2.63 x 10 24 molecules of CO. What mass of Fe is
expected? [10]

23 g

the mol of Fe is 11,5/56 = 23/112 (mol)

the mol of CO is (mol)

we have:

Fe2O3 + 3CO => 2Fe + 3CO2

23/112    69/112     23/56

=> the mol of Fe is 23/56 mol

=> the mass of Fe is 23/56.56 = 23 (g)

Explanation:

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation: